Wireless telegraphy.



in. 813,975. PATENTED FEB. 27, 1906 J. F. KING.

WIRELESS TELEGRAPHY.

APP'LIGATION FILED JAN. 8, 1903.

Witmaooc'o wozmugg IINITED STATES PATENT OFFICE.

Specification of Letters Patent.

WIRELESS TELEGRAPHYQ Patented Feb. 27, 1906.

1 Application filed January 8, 1903. fierial No. 138,276.

To all whom it may concern.-

Be it known that I, JAMES FOSTER KING, a citizen of the United States, residing at Wash ington, in the District of Columbia, have invented certain new and useful Improvements in Wireless Telegraphy; and I-do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

More especially, my. invention relates to those wireless or space teleg'raphs in which the receiving apparatus depends for its operation upon the conjoint action of a generator current or currents, by which a receiver is constantly or normally excited. and one or more received main generator-circuit 1, 2.

oscillations, This idea is United States Patent N 0. me May 26, 1903. a

The present invention is specifically different from that shown in the patent above rebroadly covered by ferred to, principally in the following respect:

The method employed in the patented invention consists in augmenting the currentin a normally closed receiver-circuit ,by impressing thereon an extra electromotive force in;

duced by the reception of one or more oscillations. The present invention contemplates normally impressing local generatorcurrents on two branch circuits, causing the currents in said circuits to setup opposing magnetic fields; one of which is normally stronger than the other, subjecting a body normally to the opposing actions of said fields, and causing received oscillations to act to vary the normal relation between said fields.

- My invention will be more clearly understood by referring to the accompanying diagram, which shows one arrangement of circuits and apparatus by which the invention may be carriedout.

Referring to the accompanying diagram, A represents a vertical wire 'in circuit with which is connected a primary 1) of a trans former B.

C indicates a generator of alternating orother periodical currents connected to a This main generator-circuit divides into two branch circuits 3 and 4. y

D represents what I shall designate a differential relay having two coils d, (1, adapted to create opposing magnetic fields which are madeto act upon a tongue (P. The tongue of this relay is normally pulled by spring d against a spring-plunger d into close proxim- 729,497, granted to with secondaries b of the transformer B, while coil d is connected in the branch circuit 3.

E indicates a telegraphic sounder or other receiving device connected in the relay-circuit 5 together with the battery F. o

The currents in the main circuit 1, well as the branch circuits 3 and 4, may be brought into proper phase with the several electromotive forces acting in the respective circuits, and thereby produce maximum re sulting .magnetic effects at the poles, by a proper adjustment of condensers G, Gf and G Th also to prevent foreign oscillations from affecting the relay D.

Although I have shown the 'coils d and d wound upon iron cores, there are conditions under which iron may be omitted.

The facing poles set up by the current in the coils [Z and d oppose each other, that is, the two fields exert force in opposite directions on the tongue (1*. Owing to the impedance feet on the tongue (1 This-is the normal condition under which the tongue d is held away from the forward contact d When a received oscillation impinges on the vertical wire, this will set up an induced electromotive force in the secondaries of the transformer B, which, added to the normal electromotive force of the branch circuit 4, will cause the magnet-coil d to increase its pull to such an extent as to reduce the preponderating pull -of the coil (Z sufficiently to allow the spring (1 to pull the tongue d against the contact (1, thus sending current through the local receiving device E, as will be readily understood.

1. The method of receiving wireless-telegraph messages' which consists in normally impressing local generator-cin'rents on two branch circuits, causing the currents in said circuits to set up opposing magnetic fields one of which is normally'stronger than the other, and causing received oscillations to act to vary the normal relation between said fields.

ity to a forward contact-stop (F. The coil (1- 1s connected in the branch circuit 4 in series e condensers G, and G may serve in the circuit 4 introduced by the second aries' will, therefore, exercise a preponderating ef-l over that of the coil (1.

Having thus described my invention, what 2. The method of receiving Wireless-'teleceived oscillations to actto vary the normal graph messages whichconsists in normally l v impressing local generator-currents on two In testimony-whereof I affix my signature branch circuits, causing the currents in said in presence of two Witnesses.

circuits to set up opposing magnetic fields JAMES FOSTER KING.

one of which is normally stron er than the Witnesses; other, subjecting a bod normal y to the op- JOHN H. HOLT, posing actions of said elds, and causing re- FRED W. ENGLERT.

relation between said fields. 10 r 

